Fire ants writhe to make unsinkable rafts

Swarms of the insects link up in vast groups to float across water, but how they withstand waves and other forces that threaten to sink them wasn’t known.

The ants form the rafts by grasping each other’s legs and jaws. David Hu at the Georgia Institute of Technology and his colleagues used micro-scale computer tomography and high-speed video to look more closely as they crushed and poked the rafts in the lab. They discovered that the structures are able to stay afloat and flow around objects because the ants are continually detaching from and reattaching to each other.

Presented this week at a physics meeting in Pittsburgh, the work could help engineers to program self-assembling robots or develop materials that are stretchy, waterproof and shock-resistant.

This article appeared in print under the headline “How fire ants build unsinkable rafts”